This invention relates to centrifugal separators and, more particularly, to improvements in vertical centrifugal separators which extend the useful life of various components within the separator, thereby reducing downtime of a separator and decreasing its maintenance.
As is well-known, centrifugal separators are widely used in a variety of processes in which material separation is required. Typically, material is fed into a top of the separator and is brought into contact with rotating elements within the separator. Solid material is retained near the center of the separator; while, free liquids are slung off, by centrifugal force, to the outside of the separator. These liquids are then directed to a drain outlet, and the solid material falls, by gravity, to the bottom of the separator from whence it is discharged and collected.
Because of the abrasive quality of the material fed into a separator, and the impact forces which are created as the material is moved through it, components within the separator are subject to reasonably rapid wear. Screens, rotors, etc., all need to be replaced with such frequency, that a separator has a substantial downtime while necessary maintenance is being performed.
The maintenance problem with centrifugal separators has long been recognized and different measures have been undertaken to address it. In U.S. Pat. No. 4,961,722, for example, a screen assembly is described having separate upper and lower portions. These portions are separate because in conventional centrifugal separators, the screen assembly projects as far upwardly within the separator housing as a flight assembly of the separator. In use, material introduced into the separator is flung against the screen. It then falls by gravity down the flight assembly which is mounted within the perforated sidewall of the screen. Because of the impact forces of the material against the screen, the upper portion of the screen rapidly becomes torn and needs frequent replacement. In this U.S. Pat. No. 4,961,722 patent, having a separable upper and lower screen portion facilitates replacement of the screen portion subjected to this greater wear, thus reducing downtime and maintenance costs since only part, not all, of the screen is replaced and this requires only a limited tear down of the inner portion of the separator.
While the above may be effective for its intended purpose, it will be appreciated that other portions of the separator are also subjected to wear and the capability of extending the useful life of these components will further reduce downtime and maintenance costs.
Other prior art United States patents showing related developments are disclosed in the patent to Chance, U.S. Pat. No. 1,664,769; the United States patent to Howe, U.S. Pat. No. 2,043,662; the United States patent to Pate, U.S. Pat. No. 2,727,631; the United States patent to Van Riel, U.S. Pat. No. 2,752,043; the United States patent to Strong, U.S. Pat. No. 3,074,842; and the prior art United States patent to Quetsch, U.S. Pat. No. 3,361,264.